William hay



Pafented Apr. 25, I899.

W. HAY. SAFETY ELEVATOR BRAKE.

(Applicatien filed Feb. 5, 1698.)

(Model.)

24 /WSW j Z. 75W

ATTORNEYJ Uivrrnn STATES WV'ILLIAM HAY, OF NEWV YORK, N. Y,

SAFETY ELEVATOR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 623,663, dated April25, 1899.

Application filed February 5, 1898. erial No. 669,219. (ModeL) T0 ctZZwhom, it may concern.-

lfie it known that I, ILLIAM HAY, a subject of the Queen of GreatBritain, residing at New York, in the county of New York and State ofNew York, have invented certain new and useful Improvements in SafetyElevator-Brakes, of which the following is a full and completespecification, such as will enable those skilled in the art to which itappertainsto make and use the same.

This invention relates to safety elevatorbrakes; and it has for itsobject to provide a simple and improved brake mechanism which willnormally operate as the guide-rack and guide devices for the side of thecar, but which will instantly and automatically perform its function asa brake when the weight of the car is received upon said brake mechanismeither through the release of the car from suspension by breaking of itssuspendingcables or from any other cause.

The invention is fully disclosed in the following specification, ofwhich the accompanying drawings form a part, in which the separate partsof my improvement aredesignated by the same letters of reference in eachof the views, and in which- Figure 1 is a side view showingan elevatorprovided with my improved safety-brake and guide mechanism, the car andmechanism being in normal suspended condition. Fig. 2 is a side viewtaken on a plane at right angles to Fig. l and showing the brakemechanism in operative position with the car released from suspension.Fig. 3 is a detail inverted plan view, partly in section, showing thebrake devices; and Fig. 4 is a detail side view of the worm-wheel. I

Referring to the drawings, A designates the elevator-car, which issuspended by the usual rope or cables at and is adapted to travelbetween the vertical guide-bars B B, plates or shoes to being providedupon the car for the engagement of said guide-bars.

In carrying out my invention the guide-bars B are formed by a worm-gearrack-bar having its teeth Z) inclined with respect to the horizontalplane of the car. The worm-gear rack bar is engaged by a worm-wheel G,mounted in horizontal position upon the bottom of the elevator-car. Thisworm-wheel is preferably carried in a suitable bracket, as at d, inwhich it is loosely mounted, so that a degree of play vertically ispermitted. The worm-wheel is preferably loosely carried by a verticalshaft 6, arranged in the bracket (Z. The relative construction andarrangement are such that when the car is in normal suspended positionand traveling either upwardly or downwardly the weight of the car willbe entirely carried by its suspending media and no weight will becarried by the loosely-mounted worm-wheel O. The latter will thereforerevolve freely in the worm-gear rack-bar B, and by reason of its loosemounting upon its shaft 6 and the degree of vertical play permitted inthe bracket 01 it will not retard the motion of the car in eitherdirection; butwhen the car is released from suspension by breaking ofthe suspending rope or cable, or for any other reason the weight of thecar rests upon the worm wheel 0, the latter will bind between the teethof the rack-bar and the bottom of the car and cannot turn, so that it islocked in firm engagement with the rack-bar and sustains the car infixed position. The upper part of the bracket 61 forms a bearing-surfaceor stop, against which the top surface of the worm-wheel G will bear inthe brake operation just described, and which also limits the upwardmovement of said wheel, while the lower part of said bracket formsa-stop to limit the downward movement of said wheel.

In the ordinary movement of the elevatorcar the car and the worm-gearwill move at uniform speeds, and consequently the car will not beretarded in its movement by the wormgear. In the case of a certainincrease in the velocity of the car, however, the worm-gear will ofcourse by reason ofits inertia fail to move immediately atthe samevelocity, and consequently will be brought in contact with the bracketdirectly beneath the floor of the car. This will exert abraking actionon the worm-gear and stop its movement. The wormgear will consequently,together with the rackbar, serve as a brake and will stop or support thecar, and the car will also at this time be still further supported bythe slight tipping TOO occasioned by its being supported at one sideonly.

IIaving fully described my inven tion, I claim as new and desire tosecure by Letters Patent 1. An improved safety elevator-brake,comprising a vertical worm-gearrack-bar extending the length of theelevator-shaft at one side thereof, an elevatorcar, a stationary shafton the bottom of said car, and at one side thereof, a worm-gear looselymounted on said shaft and adapted to have vertical movement thereon, andalso to mesh with said rack-bar and stops which limit the movement ofsaid wormgear in both directions of its vertical movement, substantiallyas shown and described.

2. The combination with an elevator-car, of a bracket. or supportsecured to the bottom thereof near one side thereof, a vertical shaftmounted-in said bracket or support, a wormgear mounted on said shaft andadapted to move vertically thereon within certain limits, the verticalmovement of said worm-gear being limited by the top and bottom of saidbracket or support, and a stationary vertical worm-gear rack-baradjacent to the said side of said car in connection with which the saidworm-gear operates, substantially as shown and described.

3. Theherein-d escribed brake for elevatorcars, comprising thecombination with a car, of a suitably-supported vertical shaft securedto the bottom of the car adjacent to one side thereof, a worm-gearmounted on said shaft and adapted to move vertically thereon withincertain limits, and a stationary Worm-gear rack-bar supported adjacentto said side of the elevator-carand in connection with which

